Definition: You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.
Input: Question: What is the greatest integer m for which the number 40!/10^m is an integer?

 Option A: 7

 Option B: 8

 Option C: 9

 Option D: 10

 Option E: 11

Option C